I used a 10 inch slant disc in my Valiant with the 273. It fit the 9 1/2 in. pressure plate and fly wheel that was in the car when I bought it. It was a big improvement over the 9 1/2 in. It doesn't slip, but now the tires do.
Me too, on the 10". After messaging with Toolmanmike, I ordered one from Brewers. I thought I was having problems with it so I called Brewers and once he explained the fine art of adjusting a three-fingered clutch with an override spring at the pedal, I saw the light, followed his instructions, and it works like a champ.